As we have tested the above X11 session scenario (login as "Guest" without the
/usr/bin/X11 in the search PATH) we won't get into the "hung" situation. It is
true that the screen displays, "Starting session for Guest...", if no one
presses the Return key.
At that "hung" point, however, if you only press Return, the default X11
session will come up. The default X11 session includes a "Console" window, two
"xterm" windows, and three X client applications (xlogo, xload, and xclock). If
you have pressed any printable key then Return, it will bring you back to the
Login dialog box.
As we examine the /usr/bin/X11/X11 script, the above behavior becomes clear,
because the X11 script does check if /usr/bin/X11 is in your search path, then
asks you if it should be appended to your search path. This is why the
"Starting session for Guest..." message was waiting for your reply.
Note that the "x11debug.log" file will be created under the user's home
directory, if any error is encountered. Check with that file for an
explanation.